Calcium plays a vital role in the health of cats, especially in maintaining the strength and density of their bones. Just like in humans, calcium is essential for ensuring that a cat’s skeleton remains sturdy, as well as for the normal function of muscles and nerves. When there's an imbalance, it can lead to serious conditions, including brittle bones, which puts cats at risk of fractures and other complications.

So, what causes these calcium imbalances in cats, and how can vets recognise and manage this condition?

The Role of Calcium in Cats

Calcium is not just a building block for bones and teeth; it also regulates muscle contractions, nerve transmission, and blood clotting. The bones act as a reservoir for calcium, storing excess amounts and releasing it into the bloodstream when required. A fine balance of calcium in the body is essential for all these processes to function smoothly.

Cats need calcium in their diet, which is usually provided through commercial pet foods or supplemented when necessary. However, when this balance is disrupted—whether due to poor nutrition, underlying health conditions, or other factors—calcium imbalances can occur, potentially leading to brittle bones, muscle weakness, or other systemic issues.

Causes of Calcium Imbalance in Cats

There are several reasons why a cat might develop a calcium imbalance, with some of the most common causes outlined below.

1. Nutritional Deficiencies or Imbalances

A poor or unbalanced diet can lead to calcium deficiencies, especially if the diet lacks essential nutrients like vitamin D, which helps absorb calcium. Cats on homemade diets or those consuming foods not properly formulated may be at risk of this deficiency.

2. Hyperparathyroidism

This condition occurs when the parathyroid gland becomes overactive, leading to an excess of parathyroid hormone (PTH) production. PTH regulates calcium levels in the blood, and when overproduced, it causes the body to release too much calcium from the bones, leading to a condition known as hypercalcaemia. Over time, this can weaken the bones, making them brittle and more prone to fractures.

3. Chronic Kidney Disease

Chronic kidney disease (CKD) is a common ailment in older cats and can disrupt the balance of calcium and phosphorus in the body. As the kidneys fail to properly filter waste products, the body attempts to compensate by altering calcium metabolism, which can result in bone demineralisation and brittleness.

4. Vitamin D Deficiency

Vitamin D helps regulate calcium absorption from the gut. Without adequate vitamin D, calcium absorption decreases, leading to lower calcium levels in the bloodstream and an increase in calcium release from bones, making them weaker over time.

5. Hypocalcaemia

Hypocalcaemia refers to abnormally low levels of calcium in the blood. It can occur due to poor diet, pancreatitis, or complications from certain medications. If left untreated, it can lead to seizures, muscle tremors, and brittle bones in severe cases.

Recognising Calcium Imbalance in Cats

For veterinary professionals, identifying a calcium imbalance early is critical. Signs that a cat might be suffering from a calcium-related issue include:

• Lethargy or Muscle Weakness: Cats may become less active, struggle with mobility, or show signs of muscle weakness.

• Bone Pain or Lameness: Cats with brittle bones may show signs of discomfort or reluctance to move, and may even develop limps due to fractures or other skeletal issues.

• Seizures or Muscle Tremors: In cases of severe hypocalcaemia, cats may experience seizures, muscle tremors, or involuntary twitching.

Diagnosing Calcium Imbalance

When a calcium imbalance is suspected, thorough diagnostic work is necessary. This includes:

• Blood Tests: Measuring calcium, phosphorus, and parathyroid hormone levels can give insight into whether an imbalance is present and, if so, what the likely cause is.

• X-rays or Bone Scans: Imaging can be used to assess bone density and detect fractures or areas of bone weakness.

• Urine Tests: Checking kidney function can be essential, especially in older cats, to rule out chronic kidney disease.

Treatment Options

Treating calcium imbalances in cats depends on the underlying cause. If the problem is dietary, adjusting the cat's nutrition may be enough to restore balance. For example, switching to a specially formulated diet that provides the correct levels of calcium, phosphorus, and vitamin D can help.

In cases of hyperparathyroidism, surgery to remove the overactive gland may be necessary. If kidney disease is the cause, managing the condition through medication, diet, and fluid therapy can help control calcium levels and protect bone health.

Preventing Calcium Imbalances in Cats

Prevention is always preferable to treatment. Ensuring cats receive a well-balanced, nutritionally complete diet is the first step in avoiding calcium imbalances. Regular check-ups with a veterinarian can help catch any early signs of imbalance, particularly in older cats or those with existing health conditions like CKD.

Veterinary professionals should educate pet owners on the importance of appropriate nutrition and the risks of homemade or improperly balanced diets. Monitoring cats for signs of bone weakness, especially as they age, and addressing any issues promptly can help maintain their health and quality of life.

Conclusion

Calcium imbalance can be a serious condition for cats, particularly as it relates to bone health. By understanding the causes, signs, and treatment options, veterinary professionals can play a key role in managing and preventing this condition. With proper diagnosis and care, cats with calcium imbalances can go on to lead healthier, more comfortable lives.

References:

• VetHelpDirect. (2024). "Calcium Imbalance in Cats: Why Does My Cat Have Brittle Bones?" Retrieved from VetHelpDirect.